In a variety of semiconductor power applications, chip diagnostic functions and protection circuits are required, for example in power drivers for automotive and industrial applications such as protected low side, high side and bridge configurations or complete power system integrated circuits (ICs). Power devices and analog and digital circuits may be combined by monolithic integration in a single chip in so-called “Smart Power” or “BCD” (Bipolar CMOS DMOS) technologies. Smart Power technologies may be classified with respect to isolation technique, for example self-isolation, junction isolation, or dielectric isolation, or with respect to a type of the power device, for example specification of a direction of current flow.
Electric isolation of neighboring circuit elements, for example bipolar junction transistors (BJTs) or field effect transistors (FETs) is required to allow each of the circuit elements to be operated in the specified operational voltage range, thereby avoiding the risk of electric breakdown of circuit elements within the specified operational voltage range, for example. Hence, it is desirable to improve electric isolation techniques of semiconductor devices.